Method of authenticating device using photographed image and system therefor

1. A method for an authentication device to authenticate a target device, the method comprising: photographing, by the authentication device, at least some region of the target device to generate a photographed image; comparing, by the authentication device, a photographed image with a previously stored reference image; connecting, by the authentication device, to the target device over a short distance communication network responsive to similarity between the photographed image and the reference is greater than a threshold; transmitting, by the authentication device, a verification request to the target device through the short distance communication network; recognizing, by the authentication device, a verification response from the target device; and transmitting, by the authentication device, a result of the verification to the target device.

2. The method of claim 1 , further comprising previously registering, by the authentication device, the target device before photographing the at least some region of the target device.

3. The method of claim 2 , wherein previously registering the target device comprises: connecting the authentication device and the target device over the short distance communication network; photographing, by the authentication device, the at least some region of the target device; and storing, by the authentication device, the photographed region of the target device as the reference image.

4. The method of claim 1 , further comprising: receiving, by the authentication device, location information from the target device before transmitting the verification request to the target device; and comparing, by the authentication device, current location of the authentication device with the location information of the target device, wherein transmitting the verification request to the target device is performed when a distance value between the location of the authentication device and the location of the target device is smaller than a threshold.

5. The method of claim 1 , wherein comparing the photographed image with the previously stored reference image comprises: extracting a plurality of feature points from the photographed image; and comparing the plurality of extracted feature points with the reference image.

6. The method of claim 1 , wherein: recognizing the verification response of the target device comprises recognizing, by the authentication device, an output screen of the target device, and transmitting the result of the verification to the target device comprises transmitting, by the authentication device, a value calculated based on the output screen to the target device.

7. The method of claim 6 , wherein the output screen of the target device comprises a plurality of randomly combined colors.

8. The method of claim 6 , wherein: recognizing the output screen of the target device comprises recognizing, by the authentication device, at least some region of the recognized output screen and calculating RGB values based on colors within the recognized region, and transmitting the value calculated based on the output screen to the target device comprises transmitting, by the authentication device, the calculated RGB values to the target device.

9. An authentication system, comprising: an authentication device configured to generate a photographed image by photographing at least some region of a target device to generate a photographed image, compare the photographed image with a previously stored reference image, connect to the target device over a short distance communication network responsive to similarity between the photographed image and the reference image is greater than a threshold, transmit a verification through the short distance communication network, recognize a verification response from the target device, recognize a verification response from the target device, and transmit a result of the verification response to the target device; and the target device configured to perform the verification step along with the authentication device and release locking based on a result of the verification.

10. The authentication system of claim 9 , wherein the verification step is performed through a medium of an output screen from the target device in response to the verification request of the authentication device.

11. The authentication system of claim 10 , wherein the output screen comprises a plurality of randomly combined colors.

12. The authentication system of claim 10 , wherein: the authentication device recognizes at least some region of the output screen, calculates RGB values based on colors within the recognized region, and transmits the calculated RGB values to the target device, and the target device permits a connection with the authentication device if the RGB values received from the authentication device correspond to a plurality of colors included in the output screen by the target device.

13. The authentication system of claim 9 , wherein the authentication device receives location information from the target device and performs the verification step if a distance value between the location of the target device and a location of the authentication device is smaller than a threshold.

14. A non-transitory computer-readable recording medium storing instructions thereon, the instructions when executed by a processor cause the processor to: photograph at least some region of a target device to generate a photographed image; compare the photographed image with a previously stored reference image; connect to the target device over a short distance communication network responsive to similarity between photographed image and the reference image is greater than a threshold; transmit a verification request to the target device through the short distance communication network; recognize a verification response from the target device; and transmit a result of the verification to the target device.